No Further Blood Work Required When Source Patient Tests Negative
If the source patient tests negative for HIV, hepatitis B, and hepatitis C, baseline testing or further follow-up of the exposed healthcare worker is normally not necessary. 1
Key Management Principles
When Follow-Up Can Be Discontinued
The CDC explicitly states that if the source person is seronegative for HIV and has no clinical evidence of AIDS or symptoms of HIV infection, no further testing of the source is indicated. 1
Baseline testing or further follow-up of the healthcare worker normally is not necessary when the source patient is HIV seronegative. 1
This same principle applies to hepatitis B and hepatitis C—when the source tests negative for HBsAg and anti-HCV, routine follow-up testing is not required. 2, 3
The One Important Exception
If the source person has recently (within the last 3-6 months) engaged in high-risk behaviors for HIV transmission, baseline and follow-up HIV-antibody testing at 3 and/or 6 months post-exposure of the healthcare worker should be considered. 1
High-risk behaviors include injecting drug use, sexual contact with a known HIV-positive partner, unprotected sexual contact with multiple partners, or receipt of blood products before 1985. 1
However, the CDC notes it is unclear whether this follow-up testing is truly useful, as healthcare workers who become infected generally seroconvert before repeat testing of a source would normally be performed. 1
Baseline Testing Still Recommended
Even when the source is negative, perform baseline testing of the exposed healthcare worker to establish serostatus at the time of exposure. 2, 3
This includes HIV antibody, hepatitis B serology, and hepatitis C antibody testing. 2, 3
This baseline documentation protects both the healthcare worker and institution should any questions arise later about the timing of potential infection. 2, 3
Common Pitfalls to Avoid
Do not skip testing the source patient when possible—this information is critical for determining whether any follow-up is needed at all. 2, 3
Do not confuse "baseline testing" with "follow-up testing"—baseline testing of the exposed worker is still appropriate even with a negative source, but serial follow-up testing at 6 weeks, 3 months, and 6 months is not necessary. 1, 2
Serologic testing should still be made available to all healthcare workers who are concerned they may have been exposed, regardless of source status, to provide reassurance. 1